Hello J.A.W.
You write:
“your asymmetric design is of interest.. & best wishes on successful realization of it 'in metal'.”
Thank you.
The following version seems the fittest for realization in metal.
It has the typical arrangement, with one only hybrid port “looking” forwards and one intake port at the back of the engine.
The width of the hybrid port along the periphery of the cylinder liner is nearly 180 degrees.
The duration of the hybrid port is 180 crankshaft degrees:
The port at the lower side of the (red) rotary valve, in cooperation with the (blue) piston, controls the intake port of the engine:
The rotary valve (red) rotates at crankshaft speed (1:1).
The exhaust port side:
The intake side:
The Exhaust Ports area and the Transfer Ports area versus the crank angle:
Is as in the version with the half-speed rotary valve and the “double” ports.
According this plot, the variable exhaust and intake of the conventional two-strokes seem as not necessary for the PatATE because it separates the cycle in a “4-stroke-like” way:
after the expansion it follows a rapid opening of the exhaust port and the pressure drops quickly,
then the transfer opens progressively with the exhaust still opening,
then the exhaust starts progressively to close with the transfer opening more and more,
then the exhaust closes with the transfer being still widely open,
finally the transfer closes and the compression starts.
Its operation is closer to a 4-stroke with extreme valve overlap (say, as the Cosworth DFV with the 116 crank degrees valve overlap) than to a conventional 2-stroke.
Thanks
Manolis Pattakos